The present invention relates to a process for treating molten steel particularly steel which has been deoxidized and quieted and killed.
It is known generally that molten steel will accept and include nitrogen upon being in contact with air. This phenomenon was particularly observed during the so called Thomas process. On the other hand, it is well known that certain grades of steel should not include a particular amount of nitrogen particularly because of the nitrite curing. This so called nitrite curing has been reduced or even eliminated in the past through the addition of components having a certain affinity to nitrogen such as vanadium, aluminum or titanium. On the other hand, this particular approach brings with it a reduction in the capability of the resulting steel concerning hot working deformation. Moreover, steel made with an eye on very high strength may, however, exhibit a reduced weldability by this procedure. Generally speaking, it appears that the maximum content of nitrogen that can be tolerated for a variety of reasons and in different grades of steel is about 0.005%.